SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c8c87e72fd4cb63565a92ee9ba784dbd89a231e4295f4f95e48218e02b31ff5' 
  AND token = 'aPm0HRHKPwZ1HYHmFmCKV1/z0KCnHoYfLr6vn9EaJRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}